Maximum Exhaustion Research Articles

Strength and functionalized borage biochar for effective elimination of nickel contamination: Insight into batch and dynamic flow mode treatment applications

A silica gel-modified borage biochar (BB@Si) was first produced and used as a binding agent for potentially hazardous Ni2+ ions in aqueous systems. The recommended biochar was more effective in eliminating Ni2+ than pristine biochar (BB). Its maximum qm could reach up to 1.39 × 10−3 mol/g at 30 °C, and sorption isotherms showed that the Langmuir model could more accurately define its sorption behavior. The Dubinin-Radushkevich isotherm also revealed that the average sorption energy ranged from 11.00 to 11.14 kJ/mol. Zeta potential tests, SEM images, and FT-IR scans confirmed the interactions between BB@Si and Ni2+ ions. Dynamic flow treatment studies showed high uptake effectiveness when the flow rate and amount of BB@Si were suitable. Nickel desorption yield of around 80% from BB@Si was noted with 0.01 M HCl. The BB@Si column's breakthrough and exhausted points were identified to be 45 and 352 min, respectively. Its maximum exhaustion capacity value was determined to be 52.73 mg/g. Ni2+ removal from the actual wastewater sample exceeded 75%. The resulting outcomes imply the immense potential of employing BB@Si in the treatment of Ni2+– contaminated aqueous systems.

Early Pulmonary Fibrosis-like Changes in the Setting of Heat Exposure: DNA Damage and Cell Senescence.

It is well known that extreme heat events happen frequently due to climate change. However, studies examining the direct health impacts of increased temperature and heat waves are lacking. Previous reports revealed that heatstroke induced acute lung injury and pulmonary dysfunction. This study aimed to investigate whether heat exposure induced lung fibrosis and to explore the underlying mechanisms. Male C57BL/6 mice were exposed to an ambient temperature of 39.5 ± 0.5 °C until their core temperature reached the maximum or heat exhaustion state. Lung fibrosis was observed in the lungs of heat-exposed mice, with extensive collagen deposition and the elevated expression of fibrosis molecules, including transforming growth factor-β1 (TGF-β1) and Fibronectin (Fn1) (p < 0.05). Moreover, epithelial-mesenchymal transition (EMT) occurred in response to heat exposure, evidenced by E-cadherin, an epithelial marker, which was downregulated, whereas markers of EMT, such as connective tissue growth factor (CTGF) and the zinc finger transcriptional repressor protein Slug, were upregulated in the heat-exposed lung tissues of mice (p < 0.05). Subsequently, cell senescence examination revealed that the levels of both senescence-associated β-galactosidase (SA-β-gal) staining and the cell cycle protein kinase inhibitor p21 were significantly elevated (p < 0.05). Mechanistically, the cGAS-STING signaling pathway evoked by DNA damage was activated in response to heat exposure (p < 0.05). In summary, we reported a new finding that heat exposure contributed to the development of early pulmonary fibrosis-like changes through the DNA damage-activated cGAS-STING pathway followed by cellular senescence.

Mucor cells passively immobilized on rose waste phyto-biomass: An eco-friendly hybrid material for the biotreatment of reactive dye contamination

The immobilization of microbial cells on eco-friendly supports is a promising technique to obtain effectively immobilized biomaterials for the biotreatment of aquatic pollution. For the biosorption of reactive dye-contaminated water, a new immobilized biosorbent, rose waste/Mucor plumbeus cells (RWMPC) composite was designed by immobilizing the fungal cells on a process waste of the rose oil industry. Batch and continuous mode biosorption features of RWMPC under different pH, initial dye concentration, contact time, biomaterial dose, and effluent flow rate conditions were examined. Zeta potential measurements, FT-IR, and SEM analysis were used to determine the morphological features of the biomaterial and possible Reactive Blue 49 (RB49)-biomaterial interactions. Kinetic investigations revealed that Ho's pseudo-second-order kinetic model could offer the best data fitting for biosorption, while the Freudlich model best matched the equilibrium data. Immobilized biomaterial displayed a high biosorption capacity of 120.88mg g−1. With an appropriate flow rate and amount of RWMPC packed into the column, dynamic treatment tests demonstrated >90% biosorption efficiency. The breakthrough curve of the RWMPC column adequately fits Chu's simplistic model. Regeneration tests revealed that after ten consecutive cycles, the biosorption yield and recovery efficacy of RWMPC were >65 and 85%, respectively. Zeta potential tests, SEM micrographs, and FT-IR studies also verified the dye uptake. Using synthetic wastewater in a continuous system, RWMPC could remove >90% of RB49. Breakthrough and exhaustion points were identified, and the maximum exhaustion capacity value was computed as 127.6 mg g−1. The results might inspire a fresh approach to the problem of reactive dye contamination in waters.

Decreased physical performance despite objective and subjective maximal exhaustion in post-COVID-19 individuals with fatigue

IntroductionFatigue is a common symptom in post-COVID-19 patients. Individuals with fatigue often perform less well compared to healthy peers or without fatigue. It is not yet clear to what extent fatigue is related to the inability to reach maximum exhaustion during physical exercise.MethodsA symptom-based questionnaire based on the Carruthers guidelines (2003) was used for reporting the presence of fatigue and further symptoms related to COVID-19 from 85 participants (60.0% male, 33.5 ± 11.9 years). Cardiopulmonary exercise testing (CPET) and lactate measurement at the end of the test were conducted. Objective and subjective exhaustion criteria according to Wasserman of physically active individuals with fatigue (FS) were compared to those without fatigue (NFS).ResultsDifferences between FS and NFS were found in Peak V̇O2/BM (p < 0.001) and Max Power/BM (p < 0.001). FS were more likely to suffer from further persistent symptoms (p < 0.05). The exhaustion criterion Max. lactate was reached significantly more often by NFS individuals.ConclusionAlthough the aerobic performance (Max Power/BM) and the metabolic rate (Peak V̇O2/BM and Max. lactate) of FS were lower compared to NFS, they were equally able to reach objective exhaustion criteria. The decreased number of FS who reached the lactate criteria and the decreased V̇O2 peak indicates a change in metabolism. Other persistent post-COVID-19 symptoms besides fatigue may also impair performance, trainability and the ability to reach objective exhaustion.Trial registration Trial registration: DRKS00023717; date of registration: 15.06.2021 (retrospectively registered).

Marble waste derived hydroxyapatite: Low-cost adsorbent for the defluoridation of drinking water

Synthesis of hydroxyapatite (Hap) powder using waste marble powder resource was conducted in a pilot plant scale setup for its application in the defluoridation of drinking water. During synthesis, process parameters such as temperature, process time and pH were optimized so as to obtain good quality hydroxyapatite (MA-Hap LR) products. MA-Hap LR powder was characterised using FTIR, XRD which confirmed formation of purer form of Hap when synthesized at 72 °C having a crystallite size of 43.87 nm and surface area of 24.66 m2/g. SEM and TEM studies of MA-Hap LR indicated rod like morphology similar to pure Hap. The powder was pelletized via the extrusion-spheronization technique in a pelletizer using Polyvinyl alcohol as the binder. Pellets of varying size ranges (2–3 mm) were studied for their fluoride adsorption capacity. Continuous column experiments were conducted to optimize column operational parameters like inlet flow rate, input fluoride concentrations, pellet size, and bed height for maximum fluoride removal. The column fluoride adsorption capacity was obtained at 1.21 mg/g for 10 mg/L input fluoride concentration, bed height 25 cm, 1 LPH flow rate, and processed 28.5-bed volumes at a maximum adsorbent exhaustion rate of 7.4 g/L. Adsorbent regeneration studies indicated that MA-Hap LR72 pellets could be reused for three cycles. The eluent concentration required for the regeneration of exhausted pellets was optimized at 1 M NaOH, confirmed by FTIR and SEM studies of the pellets. The treated water quality was within the acceptable limits for parameters such as pH, alkalinity, hardness and TDS according to WHO and BIS regulations which describe the utility of hydroxyapatite prepared from waste marble powder as a good defluoridation agent for practical drinking water treatment applications.

Exercise testing in top athletes

Exercise testing is an essential part of the annual sports medical check-up for competitive athletes. The aim of the examination is to assess the current health status and to perform medical clearance for competitive sports. In addition, assessment of intraindividual changes over time, interindividual comparisons, and determination of training recommendations are of interest. For the assessment of cardiopulmonary fitness, abicycle or treadmill ergometry with ECG recordings is usually conducted. The exercise test is performed according to standardized exercise protocols until maximum individual exhaustion. In competitive sports, understanding of the muscular metabolic situation during exercise is crucial for assessing current exercise capacity and for managing workouts. Therefore, exercise tests are often performed as lactate performance testing or cardiopulmonary exercise test. Lactate performance testing is one of the most frequently used methods regarding exercise testing in competitive sports and is afixed component in most of the annual medical check-ups, which are performed in the sports medicine examination centers of the German Olympic Sports Confederation (DOSB). It enables the analysis of aerobic and anaerobic metabolism during exercise, which allows identification of individual endurance training intensities based on the underlying metabolism. Cardiopulmonary exercise testing is also suitable to determine the maximum oxygen uptake and to better understand medical issues related to exercise capacity.

Methodology of Estimation and Analysis of the Number of Actuations of Relay Equipment of Railway Automation and Telemechanic

Currently, the replacement of relay of railway automation and telemechanic is carried out at regular intervals without taking into account the actual number of relay switch. This method has such disadvantages as the lack of maximum and uniform exhaustion of the relay resource during operation and address planning of its replacement. The article proposes a scientific method that allows to manage the resource of relay of railway automation and telemechanic at the stage of its operation based on objective data on the values of its actual number of switch. To calculate the actual number of relay switch, simulation of the operation of relay and relay-processor systems of railway automation and telemechanic is used. The input data for the model of calculating the actual number of switch relay are the operation of the station (any movements of trains) and events that are recorded on the remote controller of the station attendant. The events of remote controller are changing the indication of the remote control lamps of the elements of the railway automation and telemechanic system (cancellation of the route, artificial opening, etc.). The article proposes to take data about the movement trains from technical diagnostics and monitoring systems. The data set, took as a result of processing information from technical diagnostics and monitoring systems, is compared with the algorithm (rules) of the operation of the railway automation and telemechanic system operated at the railway station or stage. On the results of comparing data from technical diagnostics and monitoring systems with the rules of operation of the railway automation and telemechanic system, it is formed a list of relay, describing the operating procedure of the railway automation and telemechanic system. The output data of the model is a list of relay with the actual number of relay switch. Data on the values of the actual number of relay switch allows determining the objective terms of its replacement and transition to address planning for the replacement of relay. Keywords: relay equipment of railway automation and telemechanic, number of trips, resource, control unit, train

EFEITOS DE UM PROGRAMA DE FUTEBOL REDUZIDO SOBRE OS PARÂMETROS DE SAÚDE DE CRIANÇAS OBESAS

ABSTRACT Introduction: Childhood obesity is increasing and, as a consequence, it generates health complications resulting from sedentary behavior and low levels of physical fitness. There are few studies involving children, metabolic and cardiorespiratory profiles, and soccer. Objective: The purpose was to measure the effects of a 12-week recreational small-sided soccer program on cardiometabolic risk and individual responses to cardiometabolic risk factors in overweight or obese boys. Methods: Thirteen boys aged 8-12 years (34.9±11.6% body fat) participated in a 12-week recreational small-sided soccer training program with two 80-minute sessions per week at intensities over 80% of the maximal heart rate. Anthropometric characteristics, cardiorespiratory fitness, metabolic profile, individual responses to peak oxygen uptake (VO2peak), maximal workload (Wmax), fasting blood glucose, insulin, HOMA-IR, LDL-C, HDL-C, TC, and TG were measured both pre- and post-training. Results: Considering the individual responses of the participants, recreational soccer training was effective in improving variations in maximum power and exhaustion time, as well as promoting at least one beneficial change in cardiometabolic risk factors in 84% of the overweight or obese children. There were no differences between pre- and post-program anthropometric characteristics, metabolic profiles, or VO2peak values. Conclusion: Twelve-week recreational small-sided soccer programs were able to improve maximal power and anaerobic capacity and maintain cardiometabolic risk factor levels in overweight and obese boys. Level of evidence I; High-quality prospective study (all patients were enrolled at the same stage of disease, with &gt;80% of patients enrolled) .

Effect of acute caffeine supplementation before intermittent high-intensity exercise on cytokine levels and psychobiological parameters: A randomized, cross-over, placebo-controlled trial

The present study aimed to verify the effects of caffeine supplementation on psychobiological parameters and its relationship with inflammatory cytokines in non-athlete subjects. We hypothesized that IL-10 may be responsible for the reduction in fatigue perception in response to caffeine supplementation. It was a randomized, double-blinded, cross-over, placebo-controlled study. Ten non-athlete subjects (26.9 ± 4.01 years old; 73.44 ± 9.57 kg; 15.94 ± 4.32 body fat kg) were evaluated. Sixty-min after caffeine (6 mg−1.kg−1 body mass) or placebo supplementation, high-intensity interval exercise test (1 min at 90% of Wmax and 2 min at 50% of Wmax) was performed to maximum voluntary exhaustion. Cytokine concentrations and psychobiological parameters were evaluated before (BE), immediately after (post-PE) and 1 h after exercise (1 h post-PE). We verify that IL-6 (0.35; 95% CI: 0.13 to 0.56; z = 3.24; p = 0.001; d = 1.14) and IL-10 (9.06; 95% CI 0.41 to 17.70; z = 2.05; p = 0.04; d = 1.12) increases post-PE in CAF group versus PLA group. Still, IL-10 levels were higher in CAF group 1 h post-PE (25.04; 95% CI: 8.95 to 41.31; z = 3.05; p = 0.002; d = 1.9) than PLA group. Moreover, 1 h post-PE vigor level was higher in the CAF group versus PLA group (4.53; 95% CI: 1.27 to 7.80; z = 2.72; p = 0.006; d = 0.46), and fatigue was lower in CAF group than PLA group (-5.08; 95% CI: −9.93 to −0.227; z = -2.05; p = 0.040; d = 0.67). We conclude that 1 h post-PE caffeine was able to decrease fatigue and increase vigor perception. IL-10 levels were higher 1 h post-PE in CAF group, suggesting, according to our hypothesis, that IL-10 may be associated with decrease fatigue perceptions after exercise.

Modelling and efficiency assessment of the up flow fixed bed process packed with Moringa oleifera for continuous Cd(II) removal from drinking water

The biosorption ability of ‘Moringa oleifera ‘seed powder for the expulsion of cadmium from wastewater was investigated by performing packed column tests. Column tests were conducted as a function of biosorbent dose, influent flow rate and feed sorbate concentration. The findings from column operations revealed that values of maximum cadmium uptake, exhaustion and breakthrough time enhances with rise in bed depth, reduces with rise in feed volumetric flowrate and initial cadmium concentration. At 6 g of Moringa oleifera dose, 2 mL/min of flow rate and 300 µg/L of influent cadmium, the cadmium uptake capacity was found to be 65.44, µg/g. The continuous packed column data for cadmium were well fitted to the Thomas model with the regression coefficient ranges 0.966–0.993. Moreover, the qth values obtained from Thomas model are similar to the experimental breakthrough capacities qexp. The FTIR results reveals that the Moringa oleifera seed contains various active functional groups which are appears to be played a significant role in biosorption of cadmium ions. From practical view, the Moringa oleifera seed could be utilized as safe, inexpensive, sustainable and eco-friendly biosorbent for the elimination of cadmium from drinking water using continuous column mode and also this technology could be considered as an ideal for household usage in rural communities.

Synthesis, Characterization, and Dyeing Assessment of Reactive Dyes Containing a Benzsulfonamide Moiety

A new dye intermediate and novel reactive dyes containing both azo and benzsulfonamide auxochromic groups were synthesized. Their structures were characterized by 1H-NMR, 13C-NMR, MS, IR, and UV-Vis spectral analysis. The synthesized dyes were applied to dyeing of cotton fabrics and their dyeing parameters were assessed. The new dyes exhibited improved substantivity and fixation property on cotton fabrics compared with the dye C.I. Reactive Black 5 (RB5). The maximum exhaustion and total fixation values of the reactive dyes appeared when 2 % owf of the dye concentration was used. The wash fastness and rub fastness of the new dyes reached up to 4 grade and 4–5 grade, respectively. In addition, they showed excellent fastness to light. These new dyes seem to be promising candidates for application to dyeing of cotton fibers.

Hetero-functional azo reactive dyes applied on cellulosic fabric and dyeing conditions optimization to enhance the dyeing properties

New dyestuff moieties are introduced in the textile industry to upgrade the quality and aesthetic properties of dyed fabric. To contribute to this research endeavor, the current project was conducted for the dyeing of cellulosic fabric via new hetero-functional reactive dyes R1 and R2 synthesized in our previous study. Optimization of different process variables (temperature, salt, and alkali concentration) and their interactive study for exhaust dyeing was explored and delineated based on a statistical tool response surface methodology. Results divulged that both dyes displayed maximum exhaustion and fixation at a temperature of 61.50°C on the cellulosic fabric. Reactive dye R1 exhibited 87.62 (±3) exhaustion and 82.85 (±3) fixation percentage at their optimum salt (29.07 g/L) and alkali (32.55 g/L) dosage while R2 displayed 81.50 (±3) exhaustion and 77.21 (±3) fixation at its optimized salt (32.55 g/L) and alkali concentrations (22.84 g/L). All process variables showed a positive and synergistic effect on the dyeing properties. Enhanced exhaustion and fixation percentage of R1 as compared to R2 may be accredited to greater planarity and less steric hindrance of R1. Both dyes presented superb color buildup showing good to excellent color fastness on cotton fabric. Future perspectives of the current study comprised the application and assessment of dyeing parameters of these new reactive dyes on polyester cotton (PC) fabric.

Eco-friendly dyeing of cellulosic fabric using Direct Red 28 and Direct Blue 15 dyes

&lt;p&gt;Sustainability in textiles is now a day’s key demand of consumers and traders, where the process with zero effluent emission or less emission has been considered for aim to utilize the ecofriendly process in direct dyeing of cotton to minimize effluent load. For this purpose, variable amount of Table salt and Glauber salt has been used to achieve maximum exhaustion during direct cotton dyeing. Different dyeing variables have been employed, shade made at the optimum conditions were assessed according to ISO standards. It has been found that 3g/100mL of table salt for Direct dyeing of cotton using 40mL of DR 28 (8pH) at 65oC for 45 min, whereas using 40mL of DB 15 (8pH) for dyeing of cotton at 65 °C for 45min containing 3g/100mL of Glauber slat has given acceptable color characteristics. The reduction in dyeing variable using low salt amount has proved that this method is cost, time and energy efficient process, which can be utilized for dyeing of natural fabrics using various classes of dyes to obtain sustainable textile products.&lt;/p&gt;&#x0D;

Acute effect of sodium bicarbonate supplementation by resistant training practices

Currently, the use of sodium bicarbonate (SB) as an ergogenic supplement has been linked to improved performance in several high-intensity and short time interval modalities because it is a natural buffer of the body fluids of the human body. This study aimed to evaluate the acute effect of SB supplementation on muscle strength endurance of resistance training practitioners. Crossover clinical trial, placebo-controlled (PL), and single-masked, included 10 trained adult men. The maximum repetition (1RM) and exhaustion tests with 80% 1RM were performed in the extensor chair and direct thread. In all sessions, the volunteers were verbally stimulated, the total maximum repetitions in the exercises and the blood lactate concentration were measured. SB was supplemented at a dose of 0.3 g/kg body mass. Statistical analysis was performed using SPSS version 25.0. The Shapiro–Wilk test was used to evaluate the normality of the data, and the Student’s t-test was used for independent and paired samples. The size of the Cohen’s effect was calculated, and the significance level was set at p&lt;0.05. Comparing the supplements, no significant differences were found in all variables tested. However, when comparing pretest and posttest periods, significant differences were found between lactate concentrations, with considerably large effect sizes (&gt; 1.00). SB supplementation by endurance training practitioners induces blood alkalosis, which reduces fatigue and possibly improves muscle strength endurance. Keywords: resistance exercise, ergogenic, metabolic acidosis, muscular fatigue, performance.

Altered Hemorheology in Fontan Patients in Normoxia and After Acute Hypoxic Exercise

BackgroundThe Fontan circulation is a unique palliation procedure for several congenital heart defects. Impaired exercise capacity has previously been demonstrated in these patients and also a higher risk for cardiopulmonary mortality. Hemorheology was shown to affect cardiopulmonary capacity and in turn to be affected by regular exercise and hypoxia but none of these have been investigated in Fontan patients so far. The aim of this study was to detect general differences in hemorheology in normoxia as well as possible altered hemorheological responses to hypoxia exposure and hypoxic exercise between Fontan patients and healthy controls.Methods and Findings26 Fontan patients and 20 healthy controls performed an acute exercise test (AET) on a bicycle ergometer under hypoxia with ambient 15.2% oxygen saturation (sO2). Blood samples were taken at rest in normoxia (T0), at rest in hypoxia (T1), after maximum exhaustion in hypoxia (T2), and after 50 min recovery in normoxia (T3). Hemorheological and blood parameters were investigated. Additionally, arterial stiffness was tested at T0. Red blood cell (RBC) deformability, NOx, erythropoietin (EPO) concentration, RBC count, hemoglobin (Hb) concentration and hematocrit (hct) were significantly increased in Fontan patients compared to controls. Same was observed for arterial stiffness. No changes were observed for RBC aggregation, fibrinogen concentration, free radical levels and vascular endothelial growth factor (VEGF). Hypoxia exposure did not change parameters, whereas exercise in hypoxia increased aggregation and hct significantly in both groups. Fontan patients showed significantly increased aggregation-disaggregation balance compared to controls.ConclusionAcute hypoxia exposure and exercise under hypoxia might have similar impact on hemorheology in Fontan patients and controls and was clinically well tolerated. Nevertheless, exercise alters aggregation and possibly hemodynamics which requires special attention in Fontan patients.

High-intensity exercise-induced oxidative stress in sedentary pre-pubertal & post-pubertal boys: A comparative study.

Background & objectives:High-intensity exercise results in oxidative stress in adult population. Impact of pubertal attainment on high-intensity exercise-induced oxidative stress in sedentary paediatric population has not been investigated in detail. The present study was conducted to investigate the extent of high-intensity exercise-induced oxidative stress in sedentary pre- and post-pubertal boys through estimation of serum thiobarbituric acid reactive substances (TBARS), total thiol content and activities of superoxide dismutase (SOD) and catalase (CAT).Methods:Sixty four sedentary pre-pubertal (n=32, age = 10.21±0.67 yr) and post-pubertal (n=32, age = 15.58±0.47 yr) boys performed incremental treadmill running exercise at 80 per cent of the age predicted maximum heart rate till volitional exhaustion. Blood sample (5 ml) was drawn from each individual before and after the exercise for estimation of oxidative stress markers.Results:Pre-exercise SOD activity and total thiol level showed significant positive relationship with age and were significantly higher in post-pubertal boys. Serum TBARS level, SOD and CAT activities increased while total thiol content decreased in both the groups following exercise. Post-exercise percentage change in TBARS, SOD activity and total thiol level was significantly higher in post-pubertal boys, and these variables had significant positive relationship with age. No significant intergroup variations were noted in CAT activity before or after exercise.Interpretation & conclusions:Extent of post-exercise oxidative stress increased significantly with attainment of puberty. However, baseline and post-exercise antioxidation status also increased significantly as a function of age with pubertal maturation allowing the post-pubertal boys to counter relatively higher oxidative stress more efficiently than their pre-pubertal counterparts. Post-exercise upregulation in CAT activity might not be influenced by age or pubertal maturation in this age group.

MAXIMUM EFFORT TRAINING PERFORMED IN HYPOXIA ALTERS THE MOOD PROFILE

ABSTRACT Introduction: Physical exercise at high altitude has become constant. However, the risks associated with this type of exercise represent a major concern, considering the influence of important stressors such as hypoxia and physical exercise on psychobiological and physiological responses. Objective: Analyze the mood state and behavior of physiological variables of volunteers subjected to a progressive loading protocol until they reached maximum volitional exhaustion, both at sea level and at a simulated altitude of 4500 meters. Method: For both conditions studied, the volunteers responded to two instruments that assess mood responses: The Brunel Mood Scale and the Visual Analogue Mood Scale. They also underwent blood sampling to measure blood lactate levels and to evaluate oxygen-hemoglobin saturation. These procedures were performed before, immediately after, and 30 and 60 minutes after the end of the protocol. Results: Hypoxia triggered negative effects on mood responses, especially when compared to sea level conditions. An increase in fatigue level (p=0.02) and mental confusion (p=0.04) was observed immediately after the exercise session, and reduction of vigor (p=0.03) was noted at 30 minutes, accompanied by a reduction in oxygen-hemoglobin saturation immediately after the session and at 30 minutes. There was also an increase in blood lactate levels immediately after the session (p=0.006). Conclusion: The particularities of the hypoxic environment associated with maximum exercise are able to cause a deterioration of mood and physiological responses, which can negatively modulate physical performance. This is a cross-sectional clinical study.

Heart rate dynamics during cardio-pulmonary exercise testing are associated with glycemic control in individuals with type 1 diabetes.

IntroductionThis study investigated the degree and direction (kHR) of the heart rate to performance curve (HRPC) during cardio-pulmonary exercise (CPX) testing and explored the relationship with diabetes markers, anthropometry and exercise physiological markers in type 1 diabetes (T1DM).Material and methodsSixty-four people with T1DM (13 females; age: 34 ± 8 years; HbA1c: 7.8 ± 1% (62 ± 13 mmol.mol-1) performed a CPX test until maximum exhaustion. kHR was calculated by a second-degree polynomial representation between post-warm up and maximum power output. Adjusted stepwise linear regression analysis was performed to investigate kHR and its associations. Receiver operating characteristic (ROC) curve was performed based on kHR for groups kHR < 0.20 vs. > 0.20 in relation to HbA1c.ResultsWe found significant relationships between kHR and HbA1c (β = -0.70, P < 0.0001), age (β = -0.23, P = 0.03) and duration of diabetes (β = 0.20, P = 0.04). Stepwise linear regression resulted in an overall adjusted R2 of 0.57 (R = 0.79, P < 0.0001). Our data revealed also significant associations between kHR and percentage of heart rate at heart rate turn point from maximum heart rate (β = 0.43, P < 0.0001) and maximum power output relativized to bodyweight (β = 0.44, P = 0.001) (overall adjusted R2 of 0.44 (R = 0.53, P < 0.0001)). ROC curve analysis based on kHR resulted in a HbA1c threshold of 7.9% (62 mmol.mol-1).ConclusionOur data demonstrate atypical HRPC during CPX testing that were mainly related to glycemic control in people with T1DM.

Effect of Trunk Extensor Muscle Fatigue on Postural Stability in Healthy Young Adults

Objective: To determine the effect of trunk extensor muscle fatigue on postural stability in healthy young adults using clinical measures Design: Prospective, experimental, within subject, repeated measures design Setting: Tertiary care hospital and research centre Participants: 70 healthy adults in the age group of 20 to 25 years, volunteer sample Intervention: Fatigue of trunk extensor muscles was induced by repeated dynamic contractions performed to maximum exhaustion. Postural stability was assessed under three different conditions viz. No fatigue, Fatigue and Recovery. Main Outcome Measures: One-leg standing balance test and Functional reach test were used to assess static and dynamic postural stability respectively. Results: Wilcoxon matched-paired signed ranked test was used for comparison of postural stability in No fatigue and Fatigue condition with p-value<0.001. One-leg standing balance test showed a significant decrease from No fatigue (15.16+8.47 seconds) to Fatigue (5.89+5.7 seconds) condition. Functional reach test values showed a significant decrease from No fatigue condition (12.34+2.61 inches) to fatigue condition (12.27+2.6 inches). Mean recovery time was 12.5+3.27 minutes for One-leg standing balance test and 11.93+3.22 minutes for the Functional reach test. Further analysis using Mann Whitney test showed no significant difference (P=0.288) between the recovery time of one-leg standing balance test and functional reach test. Conclusions: Trunk extensor fatigue significantly affects static and dynamic postural stability in healthy young adults. Complete recovery takes 12.5+3.27 minutes for static and 11.93+3.22 minutes for dynamic postural stability. Results of this study stress the importance of intact trunk extensor muscle function on the regulation of static and dynamic postural stability in healthy young adults. However, more studies are required to determine the effect of trunk extensor muscle fatigue using other clinical measures and in individuals with neuromuscular disorders.

Modulation of Marigold Based Lutein Dye and its Dyeing Behaviour Using UV Radiation

ABSTRACTApplication of natural dyes has increased interest in the past few years due to the eco-friendly behavior of these dyes. The present research is concerned with the effect of UV on dyeing behavior of cotton using marigold as source of natural Lutein dye. This is colorant lutein which imparts greenish yellow color to cotton fabric. The dye powder and cotton fabric were exposed to UV-radiation for different time intervals prior to dyeing and dyeing was performed at different dyeing variables. International Standard Organization (ISO) methods were employed to evaluate the color fastness properties, such as color fastness to light, washing and rubbing. It is found that 90 min exposure of UV radiations was the optimum condition for surface modification and dyeing of 70 min at 40°C give excellent results using 4 g/L salt to achieve maximum exhaustion. For improvement of color fastness, tannic acid (8%) as pre- and 6% as post-mordant is the best condition. It is found that UV ray treatment can be used to other fabrics followed by dyeing using extracts of dye yielding plants without any physical characteristics damage.